[s-cars] The 1.8t Coil Pack Conversion Shopping List

[Dave Forgie]

I've been developing this conversion in my head for a number of years
because I always thought that, eventually, our OEM coils would no longer
be made and I wanted a back-up plan for my car.  In the last four or
five months, I noticed that I was getting some missing/bucking under
WOT, and high boost, at high speed.  I figured coil (or POS) but I
didn't want to spend the money on replacing old (but perhaps robust)
technology when newer technology is out there.

I know all about the 1.8t coil pack recall on some of the Bremi-made
coil packs but I think that VW/Audi is through all that now.  For
whatever reason (excess supply, the need to do some good PR), these coil
packs are now very reasonably priced.  Since I had the need and the
price was right (about $200 - $250 for the parts versus the OEM
equivalent of about $925 for five coils and two OEM POS units), I
decided to make the conversion.  As you may have seen from my posts, it
seems to be working absolutely fine (YMMV).  Just like new OEM parts
should.  Hey, they are OEM - just from a newer technology!!

If you are interested in making this conversion, you need the parts
listed below.  They are mostly dealer parts.  I got mine through Kris at
VM Autohaus (604-298-9637) who said he would be interested in putting
"kits" together with all the parts (except items 7 and 8 that you need
to scrounge).  For Canadians, using Kris wouldn't be a bad idea. For
those in the States, there is still a bit of a gap between the US dollar
and Canadian dollars that should still make it an okay deal. However, I
know ECS tuning has the coil packs for about the equivalent price (in
absolute dollars)that I bought mine for.

Anyway, here is the shopping list:

 1.   5 units of  06B 905 115L late model 1.8t coil packs (which are
POS, coil and plug connectors all in one) should be about $25 each. Note
the "L" is very important.  DO NOT ACCEPT ANYTHING ELSE - unless they
are known to be better.

2.   5 units of  4B0 973 724 empty four wire connectors (to mate to the
115Ls) (about $10 each) (Seems expensive but they are worth it)

3.    10 pieces of  000 979 133 A - two female spade connector pig-tails
(NOTE: If I had this to do over again, I would search out the equivalent
empty pins and crimp/solder continous pieces of wire rather than spicing
these into the system.) (About $4 each piece).  These pins go into the
rear of the 4B0 973 724 four pin connectors.

4.  25 pieces of  357 972 741 A - wire sealing grommets (red) for the
4B0 973 724 connectors and 000 979 133 A wires  (about $0.30 each). They
seal the wires into the 4B0 973 724 connectors.  Install BEFORE you
connect the wires to anything else.

5.   5 pieces  6X0 971 921 A -  two-part plastic boots for the 4B0 973
724 connectors. (about $3 each).  At first I thought they were cheesy
but they are actually quite slick.  They are designed to retain 1/4"
corrugated split wire loom which helps to corral those wires.

6. 3 pieces of 000 979 134 - two male spade connector pig-tails (again,
I would search out a source of empty male pins and forget slicing these
in)

7. Two, four-pin male spade connectors to fit into the four pin female
spade connectors that carry the signal from the ECU (and a ground) and
normally fit into the four pin end of the POS units (N122 and N127).
You can search for somehting better but I found that there is a four
pin, left tail light, connector PN 191 972 704 from a the mid-90's Jetta
IIIs (might also be in some Audis because the plug has both VW and OOOO
molded into it).  These connectors are female "pin" power plugs but they
have the exactly correct pin spacing for the the OEM POS input
connectors.  They need to be modified (a lot).  But this is pretty easy.

 I bought two of these taillight plugs  with the four wires and
connectors (each).  By removing the female pins (from the connector side
with two bent paper clips to push the
 retaining pins in), you can salvage eight pins for use in the other
connector
 projects (if you want to save a few $).  Once the female pins are out,
 you need to trim off 4 mm on the nose of the connector and then remove
 all the protruding bits. I used an X-acto saw (that I have had for 40
 years when I used to make models as a kid). Don't trim much more than 4

 mm or when you load the male pins, 000 979 134 (come 2 to wire, you
need
 5 so three wires), they will push right through (don't ask how I know
 this). I think it works out that if you cut right through the center of
each O in the OOOO symbol, the amount removed is just right. You load
the 000 979 134 pins from the back.

 Once the pins are in, you can see how the newly re-gendered
 connector fits into the POS connector.  Spacing is correct but there is

 a lot of exposed, non-waterprood, non-connected, plastic to deal with.
I am planning on zap strap(s) and some silicone to solve this problem.

8.     2, three pin (male) power connectors to receive switched power
going to the primary side of the coils. These connectors are on the
connector rack on the fire wall and are the two beside the 02
connector.  You need to replace them because when you remove the OEM
coil pack, you disconnect and remove these connectors.  I cruised a
wrecking yard and found that the solution is the end of a dead three
wire VW O2 sensor (e.g. 90 to 92 Jetta II).  You need two.   The male
pin connector even has the grove to slip into the firewall bracket and
fits the power connector perfectly.  I crimped on purple power wires
that will be connected to Pin No. 1 on each of the five coil pack
connectors.

9.  Labling tape (1/2" masking tape) so you can keep all the wires
organized as to where they are going or coming from.

10. Colour-coded wire, butt connectors and good crimpers, and/or
soldering iron, solder and heat shrink tubing, 1/4", 3/8" and 1/2"
plastic wire loom, zap straps, etc.

11. Instructions and/or the S4 and 1.8t wiring diagrams (I will post the
instructions shortly)

Dave F.